Industrial lift truck



Dec. 13, 1955 s. E. RODMAN 2,726,780

INDUSTRIAL LIFT TRUCK Filed March 12, 1952 6 Sheets-Sheet l W l Zkqj. W I I 7 1 5' {J 2%. I'I [:l 1:: ll| Ill i! ii: I 6 :I

lA/VENTOR Samuel Edgar Hod/mam.

ATTORNEY Dec. 13, 1955 s. E. RODMAN 2,726,730

INDUSTRIAL LIFT TRUCK Filed March 12, 1952 6 Sheets-Sheet 2 INVENTOP 561ml Edga/r ATTORNEY Dec. 13, 1955 s. E. RODMAN 2,726,730

INDUSTRIAL LIFT TRUCK Filed March 12, 1953 6 Sheets-Sheet 3 INVENTOR MA M EBMJBL 35AM ATTORNEY 6 SheetsSheet 4 Filed March 12, 1952 Fi 4a INVENTOR Sam Lad fdga/r Roda mam.

ATTORNEY Dec. 13, 1955 s. E. RODMAN 2,726,780

INDUSTRIAL LIFT TRUCK Filed March 12, 1952 6 Sheets-Sheet 5 IN Vt NT OR Samuel, fdgg rfiodrmam.

QMM @gTmL amxm A TT'ORNE Y Dec. 13, 1955 s. E. RODMAN 2,726,780

INDUSTRIAL LIFT TRUCK Filed March 12, 1952 6 Sheets-Sheet 6 Sa/mlwL Edgar FOcZ/g a A Z $21M @Mm 3% ATTORNEY United States Patent (3 INDUSTRIAL LIFI TRUCK Samuel Edgar Rodmau, Withinlee, Presthury, England Application March 12, 1952, Serial No. 276,171

2 Claims. (Cl. 214-653) This invention relates to a self-loading transporting device of the kind in which two loading members are movable towards and away from each other for engaging themselves with or disengaging themselves from a load.

According to the invention, a self-loading transporting device of the hereinbefore specified kind has a positive connection between the two loading members which prevents each loading member from moving a substantially different amount relative to the other loading member.

The said loading members may be jointly raisable and lowerable.

The loading members are preferably movable towards and away from each other by hydraulic driving means.

The said hydraulic driving means preferably has cylinders adapted to be controllably fed with oil under pressure and rams adapted to be displaced by the said oil entering the cylinders.

There are preferably relief valves associated with the driving means for controlling the maximum oil pressure and the said valves may be adjustable.

The loading members and the means for driving them towards and/or away from each other are preferably provided on a slide or carriage which is raisable and lowerable on a guide which may or may not be tiltable.

The said positive connection may consist of rack and pinion mechanism which connects the loading members together.

Each loading member may have a rack, and each rack may mesh with the same pinion mounted on a relatively stationary part, or with at least one of two laterally spaced pinions rotatably mounted on relatively stationary parts of the device, the two pinions being connected or not by other means than the racks so as to prevent each pinion from rotating substantially without the other.

Each pinion may have a sprocket wheel connected to it, the two sprocket wheels having a chain mounted on them to prevent one from rotating without the other.

The transporting device on which the loading members are provided may be a truck or other conveyance having wheels or a tractor or conveyance which has its own track forming means.

The loading members may be two arms or jaws adapted to adjust a load into and clamp it between them in a substantially central position relative to the device by inward application to external opposed sides of the load, and/or to adjust a load into and hold it jointly in a substantially central position relative to the device by outward application to internal opposed sides of a load.

The cylinders are preferably on the slide or carriage and the rams are on the loading members; Each of the loading members may be actuated towards and away from the other by a separate cylinder and ram, and the cylinders and rams be double acting.

The said loading members may be detachably connected to the slide or carriage or brackets provided thereon to enable loading members which are of a different form and are adapted for obtaining a purchase on a load in a difierent way or for carrying a load in Fee a different way to be attached to the slide or carriage in place of the first named loading members as their use may be required.

The said slide or carriage may be carried and guided by two upright carrying members adapted to be tilted on the transporting device, and the cylinders and rams and also guide means for the loading members be provided on a dropped part of or dropped brackets on the slide or carriage to enable the said loading members to be lowered relatively close to the ground whilst making possible a substantial clearance between the lower ends of the carrying members and the ground.

In the more or less diagrammatic drawings 7 Figure l is a side elevation of a self-loading transporting device comprising a wheeled truck,

Figure 2 is a plan view of Figure 1,

Figure 3 is a detached side view, partly in section, of parts of the device, with portions broken away.

Figures 4 and 4a are fragmentary front views, partly in section, of a detached part of the said device and show different halves respectively of the said part, and

Figures 5 and 5a are similar views to Figures 4 and 4a, but with portions broken away, and parts shown in another position.

Figures 3 to 5a are drawn to a larger scale than the remaining figures.

Referring to the drawings, in the construction shown therein, as applied by way of example to a wheeled truck or a tractor or a tracked transporting vehicle employed more particularly for unloading and stocking bales or taking bales from stock and loading the same onto wagons or the like for road or rail transport, the truck 1, Figures 1 and 2, tractor or tracked vehicle is provided with an elongated guiding and supporting frame 2 mounted to swing about a horizontal axis for example under hydraulic power. The frame 2 has two longitudinal guide members 3 of channel section forming parallel guides for a slide 4 or carriage composed of two plates 5 having slide blocks or rollers 6 engaging the channels of the guide members 3 and connected together laterally and having forwardly projecting parts 7 which are dropped relative to the remaining parts of the plates 5 so that the dropped parts 7 are lower than the bottom ends of the guide members 3 when the slide 4 is in its lowest position. The dropped parts 7 register with each other and have secured to them horizontal guide tubes 8, 9, 1t), 11 extending from one plate 5 to the other and fixed to the plates 5 and situated one below another. The guide tubes 8 and 9 guide and have slidable in them slide rods 12 and 13 respectively whose ends are connected rigidly to the flanges 14 and 15 respectively of a U-bracket 16, the guide tubes 8 and 9 having slots 8' and 9' respectively to accommodate the flanges 14 and 15 of the bracket 16. The guide tubes 10 and 11 guide and have slidable in them slide rods 17 and 18 respectively whose ends are connected rigidly to the flanges 19 and 20 respectively of a second U-bracket 21, the guide tubes 10 and 11 also having slots 10 and 11' respectively to accommodate the flanges 19 and 20 of the bracket 21. The bracket 16 has provided on its web 22 lugs 23 connected by a pin 23 to the outer end of a hydraulic double acting ram '24 which faces in one lateral direction and works in a double acting cylinder 25 extending from one of the plates 5 to the other and connected rigidly to the plates 5. The bracket 21 has provided on its web 26 lugs 27 connected by a pin 27' to the outer end of a double acting ram 23 which faces in the reverse lateral direction and works in a double acting cylinder 29 extending from one of the plates 5 to the other and connected rigidly to the plates 5. The ends of the guide tubes 8 and 9 have a plate fixed to them, the plate-40 having slots 41 and 42 to allow passage therea through of the flanges 14 and 15 respectively of the U-bracket 16, The end of the cylinder 29 is also fixed to the plate 40. The guide tubes 'and 11 have a plate 43 similar'to the plate 40 fixed to their ends, the plate having slots 44 'and45ior theflange's 1-9 and 2% respectively of the Ll-bracket 21. l'hccnd 1of the cylinder .25 is also fixed to the plate 43. The plates "41) and-43 also have gaps 46; 47 respectively to allow tpassage of the rams 24" and '28 respectively. The .g-uide tubes-8, 9, 1t 11, slide rods 1 2, 13, 17, 18, rams 2-4and-28 and cylinders 25 and 29 are substantially horizontal and by the introduction ofoil under pressure into the requisite ends of the-cylinders 25 and 29 the-rams Hand 28 can beforced to corresponding inward movement of .the u b'racket 16 outwards in reverse directions -and-inwards in reverse directions, the -brackets 16 and 21 being thereby forced away from each other or towards ieach other. Each of the brackets 16 and 21 has aremovably bolted to it a rigid clamp arm 30, 31 respectively 'whichlprojects 'for wards from the-respectivebracket. I

' The cylindersZS and '29 are connected :pairwise by piping 32 ;-to 'an oil control valve or valves (not shown) whereby oil can be fed-jointly to the inner ends of both cylinders 25 and '29 and released-jointly from the outer ends thereof or can be'f'ed jointly to the'outer ends of the cylinders 25 and 29 and r'eleasedtjointly from the inner.

ends'in order to operate the rams-24 and 28 in-the hereinbefore described manner. V

In order positively to obtain an equal amount and strength of motion of the two arms 3%, 31, toothed racks 33, 34, secured for example at one end to the U-brackets 16 and 21 respectively, are provided to mesh with toothed wheels 35, 36 respectively rotatable'onstationary parts,

7 for example the plates 5 are coupledtogetherby sprocket wheels 37, 38 respectively and a driving chain-39 so that V on motion of each U-bracket taking place, the other in a closed position. In Figures 5, and 5a, the arms 30, 31

are, shown in a separated position. 7 I V In operation, for-example to unload a bale-from a lorry and deposit it in a store room, without firstsupporting the bale from below above the floor ofthe' lorry on which it rests, the slide 4 or-carriage-is operated *tobring the armsSt '31 to'a height level with the sides-of the bale,

and-the truck 1; tractor or'tra'cked transporting vehicle'is V maneuvered to bring'the thus operated slide 4 or'carriage into a position where the arms:30, 31 are situated at opposite sides of the bale, with the-bale 'between'them,

' whereupon the rams 24 and 28 are operated'to force'the arms 30, 31 towards each-other-untilthey act on the sides, of the baleand thereby'squeeze or clamp the bale between them. The lateralgrip thus obtained on the bale is sufiicient to enable-the bale to'bet lifted from the platform of the lorry without the aid of supporting means applied beneath the bale. The slide "4 'or carriage is-then raised to lift the baleclear, the truck'l, tractoror-tra'cked vehicle driven to draw'the bale away from the-fioor the slide 4 or carriage'partly lowered and the-truck 1,-tractor or tracked vehicle driven to the storing jsp'otfwhereup'on the slide 4 or carriage is further lowered to'lower the bale onto the said spot and the rams -24 and 28 are then operated to drivethe 'arms- 30, 31' away from each other and thereby release the halo. The loading of a bale from 7 store onto a lorry takes place with equalfacility-without *the need to have the bale' supported"above'the storage floor prior to the loading.

. Assuming the U-brackets, 16, 21 to be in the-position shown in Figures 5 and 5a,' preparatory tobeingmoved towards each other in order to cause the arms=30and31 to grip between them the bale resting on the said floor and projecting upwards somewhere between the said arms,

the motive liquid is forced into the cylinders 25 and 29 in order to propel the U-brackets towards the positions shown in Figures 4 andr4a. It will be, observed .thatwhen the said brackets are in the positions shown in Figures 5 and 5a, the rack 34 meshes only with the pinion 36 and the rack 33 meshes only with thepinion 35. The'sprocket wheels 37 and 38 and the driving fc'h'a in 39 however'positively connect the pinions togetherand therefore. the U-bracket 21 cannot move inwards without there being a equalling in amount substantially the inward movement of. the U-bracket 21. Therefore notwithstanding a noncentral disposition of the bale. relative to the truck, tractor or tracked vehicle, neither arm can remain stationary whilst the other arm is moving and the arms are positively caused to approach the said centre-equally and-one of them topush the balebefor'e-it'until the balefha'szarrive'd in asubstantially-central position with an arm pressing positively and with'equal force againsteach'sidexthereof. This centering connection therefore Jcompels'.the bale to 'take up a centralfpositio'n tand ;tl1e2a'rms to grip the shale only when it is'in or hastbeenzmoved by one or :other of the arms into the central position, -'thereby ensuring that the bale is automatically so .dispo'sedmelative to "the vehicle that it can be'carried along trelativelynarrow passages or through relatively narrow openings by the vehicle with reduced .danger of fouling the-Jsides ofthefpassage or opening. When the rains are operated to separateth'e U-brackets '16:and'.2l-, the:said:centering connection ensures that the farms 'shallmove substantially equal distancesoutwards andttherefore thatfree space shall be left for occupation byazloa'cl inca substantially central position relative to, the :truck, itr'a'ctor-or tracked transportingyehiclei Where the required :ext'ent idf smaximum :opening of the arms is :sulficiently small sconvenientlyitoypermit it,

eachr'ack may heiarran'ged never to move out 'of simultaneous mesh with'both pinions, or onepinion-only may tbe tpr ovide d and mounte'dfi'n a central' positionon a relatively stationary part provided ff'oritgin either of which cases the sprocket wheels 37 and 38 and driving chain 39 can be dispensed with. I g a 'It isto b'e'understoodthatthe expre'ssion :positive connection between th'e two loading members hereinbefore and hereinafter :employe'd in'cludespositiVe connections 7' other than *the racks' a'nd pini'on :or pinions, or racks,

pinions, sprocket wheels "and *driving chain hereinbefore described. it must be held Ltoinclude also other'me'chanical connections such as :lev'ers, hydraulically interconnectedrams, or ele'ctrical devices-. I a r 'Ifla bale'is to be stored'he'tween two-other b'ales and the-space available therefor is hotquite sufiicient, the

arms'can be 'inserted intothe'space an'd the ra'ms 24,28

operated-to drive the arms 3'0 and-31 apart and thereby cause themto push the two -Zother bales fu'rther apart and thereby rnake room'for the said 'bale'i Du'etothe positive connection between the arms, (they are forced to move to any "equal extent and thereforedisplacement of both of said bales is ensu'red.

Barrels or any"other-"objects'ean begripped laterally in a simila'r rhannefiby the forcing of the'arms 30,81-to wards each other, 'for lifti'ng, lowering and transport;

Pairs of arms particularly suited in {size -a'nd 'for-mfor handling objects of particular for rnamay beprovided and V interchanged for the ar'ms30, 31. Relief valves,"which ar preferably adjustable are preferably provided inconjuncabove a predeterrnined'ipr'essure to escape without-"operab ing the rams and thereby enable -7tlr'e pressure 'applied' by the arms to be 'sui'ted to theparticular-objects to be handled so that a c-lampingpres'sure sui'ficient to" ensure-safe a crushing (st itheiload materially lifting of the' -loa dwithout canbe" obtained. 1 r

The brackets 16, 21 may have removably bolted to them arms adapted to enter the interior of an object, such as a pipe or frame and, by driving the brackets 16, 21 away from each other, be forced to grip the object by being forced away from each other against two opposed internal lateral surfaces of the object, they enable such objects to be stocked in touching positions or removed from a stock in which they touch, it being unnecessary to provide accommodation between the objects in stocking or in stock for the said internally acting lifting arms.

I claim:

1. A self-loading transporting device comprising a carrier, two upright members on which the carrier is travellably mounted, means for tilting the upright members, a part on the carrier, horizontally rectilinearly movable loading members carried by the said part, hydraulic cylinders carried by the said part, hydraulic rams working in the said cylinders and connected to the loading members for driving them separately by separate drive or by joint drive, and toothed parallel racks, pinions for meshing with both racks, sprocket wheels rotating with said pinions and a driving chain connecting said sprocket wheels together, the said racks, pinions, sprocket Wheels and chain interconnecting the loading members for constraining them always to approach a substantially equal distance towards and recede a substantially equal distance from a fixed centre plane of the device even if the load when encountered by one of the loading members is not central relative to the said plane, and constraining the said hydraulic cylinders and their rams to act jointly on one loading member alone when resistance to movement of that loading member and not the other loading member is encountered.

2. A self-loading transporting device comprising in combination two separate rectilinearly movable loading members each of which is movable linearly towards the other for gripping a load between them, a separate hydraulic prime mover connected positively to each of the loading members for urging the loading members separately towards each other, in combination with a separate toothed rack rigidly connected to each loading member in parallelism, a toothed carrier wheel rotatable on the device and in constant mesh with the first of the two racks, a separate toothed carrier wheel rotatable on the said device in parallelism with the first toothed carrier wheel and in constant mesh with the second of the two racks, a separate sprocket wheel connected to each of the toothed carrier wheels to rotate therewith and a driving chain mounted on the two sprocket wheels for positively transmitting motion directly from either sprocket wheel to the other and therefore positively transmitting motion via the chain and sprocket wheels from either toothed wheel to the other and therefore positively transmitting rectilinear motion via the chain, sprocket wheels and toothed carrier wheels from either rack to the other and therefore positively transmitting rectilinear motion via the chain, sprocket wheels, toothed carrier wheels and racks in approaching directions from either of the loading members to the other and also positively transmitting the power of each prime mover to the loading member to which power is applied directly by the other prime mover when movement of the last named loading member but not the other loading member is obstructed.

References Cited in the file of this patent UNITED STATES PATENTS 2,284,238 Todd May 26, 1942 2,412,845 Stevens Dec. 17, 1946 2,461,877 Brerton Feb. 15, 1949 2,522,128 Lehmann Sept. 12, 1950 2,571,550 Ehmann Oct. 16, 1951 2,593,635 Walker Apr. 22, 1952 2,595,131 Ehmann Apr. 29, 1952 2,604,220 Frischmann July 22, 1952 2,609,114 Backofen et al Sept. 2, 1952 2,615,748 Olson Oct. 28, 1952 

